Carson makes reference to the well-known Robert Frost poem “The Road Not Taken” to urge her readers to take the road “less traveled by” instead of the smooth superhighway of modernity, which leads down the path of escalating aggression against the natural world, which could backfire on humanity. She argues that the public has a right to know the frightening risks associated with chemical controls.
Referencing Robert Frost, whose poetry celebrates the beauty of the rural Northeast that Carson, too, loves so dearly, creates a nostalgia for the beauty of the past, before this modern era of chemicals and combat against the natural world began. Carson directly challenges the public to choose between these two alternatives.
As an alternative, she suggests that it is our responsibility to choose the path of caution, of biological solutions based on careful research and ecological understanding. The availability of these biotic controls is growing as more researchers join the quest to replace pesticides with a smarter option. Carson goes on to summarize these new options.
After an entire book dedicated to the many dangers of pesticide use, Carson will devote this last chapter to a discussion of safer, more natural alternatives that take into account the interconnectedness of nature. She leaves it for the public to decide which is better.
Dr. Edward Knipling has developed a ‘male sterilization’ technique, in which sterilized males of a species are released and gradually outcompete wild males until only infertile eggs are produced. He conducted a successful proof of concept on the island of Curacao, eliminating the native screw-worm population after releasing thousands of sterilized males from a plane. The program was then replicated on a huge scale in the Southeast, with great results.
This is an example of a carefully targeted alternative, which in contrast to pesticides would have fewer consequences on other parts of the natural community. It is still a celebration of science and the future of human development, but development in the model of nature, rather than that which attempts to supersede it.
Following the success of Knipling’s work there has been a rush to develop chemosterilants that would have a similar effect as the x-rays that he used to sterilize males of the species. However, new chemicals that would be released widely must be treated with extreme caution. There have also been experiments with synthesized hormones and defensive secretions that would be more targeted than general pesticides. Synthetic sex attractant for gypsy moths, for instance, is being deployed to disorient males during mating.
These chemical alternatives are at least not explicitly poisons, and although they must be deployed with caution and proper research into their effects on the surrounding environment, they offer access to a vision of the future in which blanketed spraying, which affects entire communities indiscriminately, could become a thing of the past.
Still more methods are under examination; some researchers are working with ultrasound waves, while others have developed disease vectors that are meant to be extremely species specific, as previously discussed with the milky spore disease and the Japanese beetle in Chapter 7. Carson confidently asserts that these microbial insecticides are harmless to all but their intended targets.
Continuing her mission to educate the public about other options, Carson recalls the success of milky spore disease in controlling the Japanese. Although modern ecologists, with more research and knowledge at their disposal than Carson had when she wrote the book, would likely argue that her support of these methods seems to fail to acknowledge the dangers to the balance of an ecosystem that eliminating any member of the community can bring, her optimism is understandable relative to the intensely destructive methods of chemical control.
And, of course, there is the option of biotic control involving imported predators or parasites. Beginning with the vedalia beetles brought to California by Alfred Koebele in 1888, there is a long history of successful importations that save millions of dollars each year. Still, biological methods are underutilized outside California. Opportunity is greatest in forests, where support for natural predators like spiders, small mammals, and birds in Wurzburg and Canada has been shown to allow for a pest-resistant, balanced ecology as it was meant to be.
Returning to one of her favorite alternative models, Carson again explains the ways that importing predators or strengthening other natural checks can allow the system to correct itself, bringing pest populations under control in the way that a millennia of evolution has already provided for. Again, modern ecologists would argue that careful research is required before the introduction of any foreign species – and might argue that there are even better ways to control “pests” than to rely on using either man-made chemical control or non-native species in efforts at biological control – but Carson’s basic optimism about this tactic is more of a reflection of her attitude toward nature and man’s place within it: that man belongs within nature, and not trying to control it.
So, there exists a whole battery of alternatives to pesticides if we can make the choice to forego the flashy, arrogant chemical option. Carson compares pesticides to the crudeness of a caveman’s club, a barrage “hurled against the fabric of life.” Nature, she concludes, does not exist for the convenience of man, and cannot be controlled by him. We must not turn our modern and terrible weapons, in ignorance, against the earth that supports us.
Carson argues that pesticides, although a tempting reflection of man’s newfound power in the world, have inflated our sense of that power to a point that will lead to our destruction. If we cannot return to a place of respect for nature and the complex systems that it contains, Carson argues that we are hurrying rapidly toward a future without many of those things that have been essential to the experience of being human, and that it is our collective responsibility to exercise caution, conduct research, and slow down the pace of development to preserve our world and save ourselves.